[WATCHDOG] mpc83xx_wdt: convert to the OF platform driver
[linux-2.6/linux-2.6-openrd.git] / drivers / sbus / char / bpp.c
blobbba21e053a1bfd4d237ec873efa1ef74acc655a1
1 /*
2 * drivers/sbus/char/bpp.c
4 * Copyright (c) 1995 Picture Elements
5 * Stephen Williams (steve@icarus.com)
6 * Gus Baldauf (gbaldauf@ix.netcom.com)
8 * Linux/SPARC port by Peter Zaitcev.
9 * Integration into SPARC tree by Tom Dyas.
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/fs.h>
16 #include <linux/errno.h>
17 #include <linux/sched.h>
18 #include <linux/spinlock.h>
19 #include <linux/timer.h>
20 #include <linux/ioport.h>
21 #include <linux/major.h>
22 #include <linux/smp_lock.h>
24 #include <asm/uaccess.h>
25 #include <asm/io.h>
27 #if defined(__i386__)
28 # include <asm/system.h>
29 #endif
31 #if defined(__sparc__)
32 # include <linux/init.h>
33 # include <linux/delay.h> /* udelay() */
35 # include <asm/oplib.h> /* OpenProm Library */
36 # include <asm/sbus.h>
37 #endif
39 #include <asm/bpp.h>
41 #define BPP_PROBE_CODE 0x55
42 #define BPP_DELAY 100
44 static const unsigned BPP_MAJOR = LP_MAJOR;
45 static const char *bpp_dev_name = "bpp";
47 /* When switching from compatibility to a mode where I can read, try
48 the following mode first. */
50 /* const unsigned char DEFAULT_ECP = 0x10; */
51 static const unsigned char DEFAULT_ECP = 0x30;
52 static const unsigned char DEFAULT_NIBBLE = 0x00;
55 * These are 1284 time constraints, in units of jiffies.
58 static const unsigned long TIME_PSetup = 1;
59 static const unsigned long TIME_PResponse = 6;
60 static const unsigned long TIME_IDLE_LIMIT = 2000;
63 * One instance per supported subdevice...
65 # define BPP_NO 3
67 enum IEEE_Mode { COMPATIBILITY, NIBBLE, ECP, ECP_RLE, EPP };
69 struct inst {
70 unsigned present : 1; /* True if the hardware exists */
71 unsigned enhanced : 1; /* True if the hardware in "enhanced" */
72 unsigned opened : 1; /* True if the device is opened already */
73 unsigned run_flag : 1; /* True if waiting for a repeate byte */
75 unsigned char direction; /* 0 --> out, 0x20 --> IN */
76 unsigned char pp_state; /* State of host controlled pins. */
77 enum IEEE_Mode mode;
79 unsigned char run_length;
80 unsigned char repeat_byte;
83 static struct inst instances[BPP_NO];
85 #if defined(__i386__)
87 static const unsigned short base_addrs[BPP_NO] = { 0x278, 0x378, 0x3bc };
90 * These are for data access.
91 * Control lines accesses are hidden in set_bits() and get_bits().
92 * The exception is the probe procedure, which is system-dependent.
94 #define bpp_outb_p(data, base) outb_p((data), (base))
95 #define bpp_inb(base) inb(base)
96 #define bpp_inb_p(base) inb_p(base)
99 * This method takes the pin values mask and sets the hardware pins to
100 * the requested value: 1 == high voltage, 0 == low voltage. This
101 * burries the annoying PC bit inversion and preserves the direction
102 * flag.
104 static void set_pins(unsigned short pins, unsigned minor)
106 unsigned char bits = instances[minor].direction; /* == 0x20 */
108 if (! (pins & BPP_PP_nStrobe)) bits |= 1;
109 if (! (pins & BPP_PP_nAutoFd)) bits |= 2;
110 if ( pins & BPP_PP_nInit) bits |= 4;
111 if (! (pins & BPP_PP_nSelectIn)) bits |= 8;
113 instances[minor].pp_state = bits;
115 outb_p(bits, base_addrs[minor]+2);
118 static unsigned short get_pins(unsigned minor)
120 unsigned short bits = 0;
122 unsigned value = instances[minor].pp_state;
123 if (! (value & 0x01)) bits |= BPP_PP_nStrobe;
124 if (! (value & 0x02)) bits |= BPP_PP_nAutoFd;
125 if (value & 0x04) bits |= BPP_PP_nInit;
126 if (! (value & 0x08)) bits |= BPP_PP_nSelectIn;
128 value = inb_p(base_addrs[minor]+1);
129 if (value & 0x08) bits |= BPP_GP_nFault;
130 if (value & 0x10) bits |= BPP_GP_Select;
131 if (value & 0x20) bits |= BPP_GP_PError;
132 if (value & 0x40) bits |= BPP_GP_nAck;
133 if (! (value & 0x80)) bits |= BPP_GP_Busy;
135 return bits;
138 #endif /* __i386__ */
140 #if defined(__sparc__)
143 * Register block
145 /* DMA registers */
146 #define BPP_CSR 0x00
147 #define BPP_ADDR 0x04
148 #define BPP_BCNT 0x08
149 #define BPP_TST_CSR 0x0C
150 /* Parallel Port registers */
151 #define BPP_HCR 0x10
152 #define BPP_OCR 0x12
153 #define BPP_DR 0x14
154 #define BPP_TCR 0x15
155 #define BPP_OR 0x16
156 #define BPP_IR 0x17
157 #define BPP_ICR 0x18
158 #define BPP_SIZE 0x1A
160 /* BPP_CSR. Bits of type RW1 are cleared with writing '1'. */
161 #define P_DEV_ID_MASK 0xf0000000 /* R */
162 #define P_DEV_ID_ZEBRA 0x40000000
163 #define P_DEV_ID_L64854 0xa0000000 /* == NCR 89C100+89C105. Pity. */
164 #define P_NA_LOADED 0x08000000 /* R NA wirtten but was not used */
165 #define P_A_LOADED 0x04000000 /* R */
166 #define P_DMA_ON 0x02000000 /* R DMA is not disabled */
167 #define P_EN_NEXT 0x01000000 /* RW */
168 #define P_TCI_DIS 0x00800000 /* RW TCI forbidden from interrupts */
169 #define P_DIAG 0x00100000 /* RW Disables draining and resetting
170 of P-FIFO on loading of P_ADDR*/
171 #define P_BURST_SIZE 0x000c0000 /* RW SBus burst size */
172 #define P_BURST_8 0x00000000
173 #define P_BURST_4 0x00040000
174 #define P_BURST_1 0x00080000 /* "No burst" write */
175 #define P_TC 0x00004000 /* RW1 Term Count, can be cleared when
176 P_EN_NEXT=1 */
177 #define P_EN_CNT 0x00002000 /* RW */
178 #define P_EN_DMA 0x00000200 /* RW */
179 #define P_WRITE 0x00000100 /* R DMA dir, 1=to ram, 0=to port */
180 #define P_RESET 0x00000080 /* RW */
181 #define P_SLAVE_ERR 0x00000040 /* RW1 Access size error */
182 #define P_INVALIDATE 0x00000020 /* W Drop P-FIFO */
183 #define P_INT_EN 0x00000010 /* RW OK to P_INT_PEND||P_ERR_PEND */
184 #define P_DRAINING 0x0000000c /* R P-FIFO is draining to memory */
185 #define P_ERR_PEND 0x00000002 /* R */
186 #define P_INT_PEND 0x00000001 /* R */
188 /* BPP_HCR. Time is in increments of SBus clock. */
189 #define P_HCR_TEST 0x8000 /* Allows buried counters to be read */
190 #define P_HCR_DSW 0x7f00 /* Data strobe width (in ticks) */
191 #define P_HCR_DDS 0x007f /* Data setup before strobe (in ticks) */
193 /* BPP_OCR. */
194 #define P_OCR_MEM_CLR 0x8000
195 #define P_OCR_DATA_SRC 0x4000 /* ) */
196 #define P_OCR_DS_DSEL 0x2000 /* ) Bidirectional */
197 #define P_OCR_BUSY_DSEL 0x1000 /* ) selects */
198 #define P_OCR_ACK_DSEL 0x0800 /* ) */
199 #define P_OCR_EN_DIAG 0x0400
200 #define P_OCR_BUSY_OP 0x0200 /* Busy operation */
201 #define P_OCR_ACK_OP 0x0100 /* Ack operation */
202 #define P_OCR_SRST 0x0080 /* Reset state machines. Not selfcleaning. */
203 #define P_OCR_IDLE 0x0008 /* PP data transfer state machine is idle */
204 #define P_OCR_V_ILCK 0x0002 /* Versatec faded. Zebra only. */
205 #define P_OCR_EN_VER 0x0001 /* Enable Versatec (0 - enable). Zebra only. */
207 /* BPP_TCR */
208 #define P_TCR_DIR 0x08
209 #define P_TCR_BUSY 0x04
210 #define P_TCR_ACK 0x02
211 #define P_TCR_DS 0x01 /* Strobe */
213 /* BPP_OR */
214 #define P_OR_V3 0x20 /* ) */
215 #define P_OR_V2 0x10 /* ) on Zebra only */
216 #define P_OR_V1 0x08 /* ) */
217 #define P_OR_INIT 0x04
218 #define P_OR_AFXN 0x02 /* Auto Feed */
219 #define P_OR_SLCT_IN 0x01
221 /* BPP_IR */
222 #define P_IR_PE 0x04
223 #define P_IR_SLCT 0x02
224 #define P_IR_ERR 0x01
226 /* BPP_ICR */
227 #define P_DS_IRQ 0x8000 /* RW1 */
228 #define P_ACK_IRQ 0x4000 /* RW1 */
229 #define P_BUSY_IRQ 0x2000 /* RW1 */
230 #define P_PE_IRQ 0x1000 /* RW1 */
231 #define P_SLCT_IRQ 0x0800 /* RW1 */
232 #define P_ERR_IRQ 0x0400 /* RW1 */
233 #define P_DS_IRQ_EN 0x0200 /* RW Always on rising edge */
234 #define P_ACK_IRQ_EN 0x0100 /* RW Always on rising edge */
235 #define P_BUSY_IRP 0x0080 /* RW 1= rising edge */
236 #define P_BUSY_IRQ_EN 0x0040 /* RW */
237 #define P_PE_IRP 0x0020 /* RW 1= rising edge */
238 #define P_PE_IRQ_EN 0x0010 /* RW */
239 #define P_SLCT_IRP 0x0008 /* RW 1= rising edge */
240 #define P_SLCT_IRQ_EN 0x0004 /* RW */
241 #define P_ERR_IRP 0x0002 /* RW1 1= rising edge */
242 #define P_ERR_IRQ_EN 0x0001 /* RW */
244 static void __iomem *base_addrs[BPP_NO];
246 #define bpp_outb_p(data, base) sbus_writeb(data, (base) + BPP_DR)
247 #define bpp_inb_p(base) sbus_readb((base) + BPP_DR)
248 #define bpp_inb(base) sbus_readb((base) + BPP_DR)
250 static void set_pins(unsigned short pins, unsigned minor)
252 void __iomem *base = base_addrs[minor];
253 unsigned char bits_tcr = 0, bits_or = 0;
255 if (instances[minor].direction & 0x20) bits_tcr |= P_TCR_DIR;
256 if ( pins & BPP_PP_nStrobe) bits_tcr |= P_TCR_DS;
258 if ( pins & BPP_PP_nAutoFd) bits_or |= P_OR_AFXN;
259 if (! (pins & BPP_PP_nInit)) bits_or |= P_OR_INIT;
260 if (! (pins & BPP_PP_nSelectIn)) bits_or |= P_OR_SLCT_IN;
262 sbus_writeb(bits_or, base + BPP_OR);
263 sbus_writeb(bits_tcr, base + BPP_TCR);
267 * i386 people read output pins from a software image.
268 * We may get them back from hardware.
269 * Again, inversion of pins must he buried here.
271 static unsigned short get_pins(unsigned minor)
273 void __iomem *base = base_addrs[minor];
274 unsigned short bits = 0;
275 unsigned value_tcr = sbus_readb(base + BPP_TCR);
276 unsigned value_ir = sbus_readb(base + BPP_IR);
277 unsigned value_or = sbus_readb(base + BPP_OR);
279 if (value_tcr & P_TCR_DS) bits |= BPP_PP_nStrobe;
280 if (value_or & P_OR_AFXN) bits |= BPP_PP_nAutoFd;
281 if (! (value_or & P_OR_INIT)) bits |= BPP_PP_nInit;
282 if (! (value_or & P_OR_SLCT_IN)) bits |= BPP_PP_nSelectIn;
284 if (value_ir & P_IR_ERR) bits |= BPP_GP_nFault;
285 if (! (value_ir & P_IR_SLCT)) bits |= BPP_GP_Select;
286 if (! (value_ir & P_IR_PE)) bits |= BPP_GP_PError;
287 if (! (value_tcr & P_TCR_ACK)) bits |= BPP_GP_nAck;
288 if (value_tcr & P_TCR_BUSY) bits |= BPP_GP_Busy;
290 return bits;
293 #endif /* __sparc__ */
295 static void snooze(unsigned long snooze_time, unsigned minor)
297 schedule_timeout_uninterruptible(snooze_time + 1);
300 static int wait_for(unsigned short set, unsigned short clr,
301 unsigned long delay, unsigned minor)
303 unsigned short pins = get_pins(minor);
305 unsigned long extime = 0;
308 * Try a real fast scan for the first jiffy, in case the device
309 * responds real good. The first while loop guesses an expire
310 * time accounting for possible wraparound of jiffies.
312 while (time_after_eq(jiffies, extime)) extime = jiffies + 1;
313 while ( (time_before(jiffies, extime))
314 && (((pins & set) != set) || ((pins & clr) != 0)) ) {
315 pins = get_pins(minor);
318 delay -= 1;
321 * If my delay expired or the pins are still not where I want
322 * them, then resort to using the timer and greatly reduce my
323 * sample rate. If the peripheral is going to be slow, this will
324 * give the CPU up to some more worthy process.
326 while ( delay && (((pins & set) != set) || ((pins & clr) != 0)) ) {
328 snooze(1, minor);
329 pins = get_pins(minor);
330 delay -= 1;
333 if (delay == 0) return -1;
334 else return pins;
338 * Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
339 * errno means something broke, and I do not yet know how to fix it.
341 static int negotiate(unsigned char mode, unsigned minor)
343 int rc;
344 unsigned short pins = get_pins(minor);
345 if (pins & BPP_PP_nSelectIn) return -EIO;
348 /* Event 0: Write the mode to the data lines */
349 bpp_outb_p(mode, base_addrs[minor]);
351 snooze(TIME_PSetup, minor);
353 /* Event 1: Strobe the mode code into the peripheral */
354 set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);
356 /* Wait for Event 2: Peripheral responds as a 1284 device. */
357 rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
358 BPP_GP_nAck,
359 TIME_PResponse,
360 minor);
362 if (rc == -1) return -ETIMEDOUT;
364 /* Event 3: latch extensibility request */
365 set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);
367 /* ... quick nap while peripheral ponders the byte i'm sending...*/
368 snooze(1, minor);
370 /* Event 4: restore strobe, to ACK peripheral's response. */
371 set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
373 /* Wait for Event 6: Peripheral latches response bits */
374 rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
375 if (rc == -1) return -EIO;
377 /* A 1284 device cannot refuse nibble mode */
378 if (mode == DEFAULT_NIBBLE) return 0;
380 if (pins & BPP_GP_Select) return 0;
382 return -EPROTONOSUPPORT;
385 static int terminate(unsigned minor)
387 int rc;
389 /* Event 22: Request termination of 1284 mode */
390 set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
392 /* Wait for Events 23 and 24: ACK termination request. */
393 rc = wait_for(BPP_GP_Busy|BPP_GP_nFault,
394 BPP_GP_nAck,
395 TIME_PSetup+TIME_PResponse,
396 minor);
398 instances[minor].direction = 0;
399 instances[minor].mode = COMPATIBILITY;
401 if (rc == -1) {
402 return -EIO;
405 /* Event 25: Handshake by lowering nAutoFd */
406 set_pins(BPP_PP_nStrobe|BPP_PP_nInit, minor);
408 /* Event 26: Peripheral wiggles lines... */
410 /* Event 27: Peripheral sets nAck HIGH to ack handshake */
411 rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
412 if (rc == -1) {
413 set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
414 return -EIO;
417 /* Event 28: Finish phase by raising nAutoFd */
418 set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
420 return 0;
423 static DEFINE_SPINLOCK(bpp_open_lock);
426 * Allow only one process to open the device at a time.
428 static int bpp_open(struct inode *inode, struct file *f)
430 unsigned minor = iminor(inode);
431 int ret;
433 lock_kernel();
434 spin_lock(&bpp_open_lock);
435 ret = 0;
436 if (minor >= BPP_NO) {
437 ret = -ENODEV;
438 } else {
439 if (! instances[minor].present) {
440 ret = -ENODEV;
441 } else {
442 if (instances[minor].opened)
443 ret = -EBUSY;
444 else
445 instances[minor].opened = 1;
448 spin_unlock(&bpp_open_lock);
449 unlock_kernel();
451 return ret;
455 * When the process closes the device, this method is called to clean
456 * up and reset the hardware. Always leave the device in compatibility
457 * mode as this is a reasonable place to clean up from messes made by
458 * ioctls, or other mayhem.
460 static int bpp_release(struct inode *inode, struct file *f)
462 unsigned minor = iminor(inode);
464 spin_lock(&bpp_open_lock);
465 instances[minor].opened = 0;
467 if (instances[minor].mode != COMPATIBILITY)
468 terminate(minor);
470 spin_unlock(&bpp_open_lock);
472 return 0;
475 static long read_nibble(unsigned minor, char __user *c, unsigned long cnt)
477 unsigned long remaining = cnt;
478 long rc;
480 while (remaining > 0) {
481 unsigned char byte = 0;
482 int pins;
484 /* Event 7: request nibble */
485 set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
487 /* Wait for event 9: Peripher strobes first nibble */
488 pins = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
489 if (pins == -1) return -ETIMEDOUT;
491 /* Event 10: I handshake nibble */
492 set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
493 if (pins & BPP_GP_nFault) byte |= 0x01;
494 if (pins & BPP_GP_Select) byte |= 0x02;
495 if (pins & BPP_GP_PError) byte |= 0x04;
496 if (pins & BPP_GP_Busy) byte |= 0x08;
498 /* Wait for event 11: Peripheral handshakes nibble */
499 rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
501 /* Event 7: request nibble */
502 set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
504 /* Wait for event 9: Peripher strobes first nibble */
505 pins = wait_for(0, BPP_GP_nAck, TIME_PResponse, minor);
506 if (rc == -1) return -ETIMEDOUT;
508 /* Event 10: I handshake nibble */
509 set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
510 if (pins & BPP_GP_nFault) byte |= 0x10;
511 if (pins & BPP_GP_Select) byte |= 0x20;
512 if (pins & BPP_GP_PError) byte |= 0x40;
513 if (pins & BPP_GP_Busy) byte |= 0x80;
515 if (put_user(byte, c))
516 return -EFAULT;
517 c += 1;
518 remaining -= 1;
520 /* Wait for event 11: Peripheral handshakes nibble */
521 rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
522 if (rc == -1) return -EIO;
525 return cnt - remaining;
528 static long read_ecp(unsigned minor, char __user *c, unsigned long cnt)
530 unsigned long remaining;
531 long rc;
533 /* Turn ECP mode from forward to reverse if needed. */
534 if (! instances[minor].direction) {
535 unsigned short pins = get_pins(minor);
537 /* Event 38: Turn the bus around */
538 instances[minor].direction = 0x20;
539 pins &= ~BPP_PP_nAutoFd;
540 set_pins(pins, minor);
542 /* Event 39: Set pins for reverse mode. */
543 snooze(TIME_PSetup, minor);
544 set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
546 /* Wait for event 40: Peripheral ready to be strobed */
547 rc = wait_for(0, BPP_GP_PError, TIME_PResponse, minor);
548 if (rc == -1) return -ETIMEDOUT;
551 remaining = cnt;
553 while (remaining > 0) {
555 /* If there is a run length for a repeated byte, repeat */
556 /* that byte a few times. */
557 if (instances[minor].run_length && !instances[minor].run_flag) {
559 char buffer[128];
560 unsigned idx;
561 unsigned repeat = remaining < instances[minor].run_length
562 ? remaining
563 : instances[minor].run_length;
565 for (idx = 0 ; idx < repeat ; idx += 1)
566 buffer[idx] = instances[minor].repeat_byte;
568 if (copy_to_user(c, buffer, repeat))
569 return -EFAULT;
570 remaining -= repeat;
571 c += repeat;
572 instances[minor].run_length -= repeat;
575 if (remaining == 0) break;
578 /* Wait for Event 43: Data active on the bus. */
579 rc = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
580 if (rc == -1) break;
582 if (rc & BPP_GP_Busy) {
583 /* OK, this is data. read it in. */
584 unsigned char byte = bpp_inb(base_addrs[minor]);
585 if (put_user(byte, c))
586 return -EFAULT;
587 c += 1;
588 remaining -= 1;
590 if (instances[minor].run_flag) {
591 instances[minor].repeat_byte = byte;
592 instances[minor].run_flag = 0;
595 } else {
596 unsigned char byte = bpp_inb(base_addrs[minor]);
597 if (byte & 0x80) {
598 printk("bpp%d: "
599 "Ignoring ECP channel %u from device.\n",
600 minor, byte & 0x7f);
601 } else {
602 instances[minor].run_length = byte;
603 instances[minor].run_flag = 1;
607 /* Event 44: I got it. */
608 set_pins(BPP_PP_nStrobe|BPP_PP_nAutoFd|BPP_PP_nSelectIn, minor);
610 /* Wait for event 45: peripheral handshake */
611 rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
612 if (rc == -1) return -ETIMEDOUT;
614 /* Event 46: Finish handshake */
615 set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
620 return cnt - remaining;
623 static ssize_t bpp_read(struct file *f, char __user *c, size_t cnt, loff_t * ppos)
625 long rc;
626 unsigned minor = iminor(f->f_path.dentry->d_inode);
627 if (minor >= BPP_NO) return -ENODEV;
628 if (!instances[minor].present) return -ENODEV;
630 switch (instances[minor].mode) {
632 default:
633 if (instances[minor].mode != COMPATIBILITY)
634 terminate(minor);
636 if (instances[minor].enhanced) {
637 /* For now, do all reads with ECP-RLE mode */
638 unsigned short pins;
640 rc = negotiate(DEFAULT_ECP, minor);
641 if (rc < 0) break;
643 instances[minor].mode = ECP_RLE;
645 /* Event 30: set nAutoFd low to setup for ECP mode */
646 pins = get_pins(minor);
647 pins &= ~BPP_PP_nAutoFd;
648 set_pins(pins, minor);
650 /* Wait for Event 31: peripheral ready */
651 rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
652 if (rc == -1) return -ETIMEDOUT;
654 rc = read_ecp(minor, c, cnt);
656 } else {
657 rc = negotiate(DEFAULT_NIBBLE, minor);
658 if (rc < 0) break;
660 instances[minor].mode = NIBBLE;
662 rc = read_nibble(minor, c, cnt);
664 break;
666 case NIBBLE:
667 rc = read_nibble(minor, c, cnt);
668 break;
670 case ECP:
671 case ECP_RLE:
672 rc = read_ecp(minor, c, cnt);
673 break;
678 return rc;
682 * Compatibility mode handshaking is a matter of writing data,
683 * strobing it, and waiting for the printer to stop being busy.
685 static long write_compat(unsigned minor, const char __user *c, unsigned long cnt)
687 long rc;
688 unsigned short pins = get_pins(minor);
690 unsigned long remaining = cnt;
693 while (remaining > 0) {
694 unsigned char byte;
696 if (get_user(byte, c))
697 return -EFAULT;
698 c += 1;
700 rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
701 if (rc == -1) return -ETIMEDOUT;
703 bpp_outb_p(byte, base_addrs[minor]);
704 remaining -= 1;
705 /* snooze(1, minor); */
707 pins &= ~BPP_PP_nStrobe;
708 set_pins(pins, minor);
710 rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
712 pins |= BPP_PP_nStrobe;
713 set_pins(pins, minor);
716 return cnt - remaining;
720 * Write data using ECP mode. Watch out that the port may be set up
721 * for reading. If so, turn the port around.
723 static long write_ecp(unsigned minor, const char __user *c, unsigned long cnt)
725 unsigned short pins = get_pins(minor);
726 unsigned long remaining = cnt;
728 if (instances[minor].direction) {
729 int rc;
731 /* Event 47 Request bus be turned around */
732 pins |= BPP_PP_nInit;
733 set_pins(pins, minor);
735 /* Wait for Event 49: Peripheral relinquished bus */
736 rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
738 pins |= BPP_PP_nAutoFd;
739 instances[minor].direction = 0;
740 set_pins(pins, minor);
743 while (remaining > 0) {
744 unsigned char byte;
745 int rc;
747 if (get_user(byte, c))
748 return -EFAULT;
750 rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
751 if (rc == -1) return -ETIMEDOUT;
753 c += 1;
755 bpp_outb_p(byte, base_addrs[minor]);
757 pins &= ~BPP_PP_nStrobe;
758 set_pins(pins, minor);
760 pins |= BPP_PP_nStrobe;
761 rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
762 if (rc == -1) return -EIO;
764 set_pins(pins, minor);
767 return cnt - remaining;
771 * Write to the peripheral. Be sensitive of the current mode. If I'm
772 * in a mode that can be turned around (ECP) then just do
773 * that. Otherwise, terminate and do my writing in compat mode. This
774 * is the safest course as any device can handle it.
776 static ssize_t bpp_write(struct file *f, const char __user *c, size_t cnt, loff_t * ppos)
778 long errno = 0;
779 unsigned minor = iminor(f->f_path.dentry->d_inode);
780 if (minor >= BPP_NO) return -ENODEV;
781 if (!instances[minor].present) return -ENODEV;
783 switch (instances[minor].mode) {
785 case ECP:
786 case ECP_RLE:
787 errno = write_ecp(minor, c, cnt);
788 break;
789 case COMPATIBILITY:
790 errno = write_compat(minor, c, cnt);
791 break;
792 default:
793 terminate(minor);
794 errno = write_compat(minor, c, cnt);
797 return errno;
800 static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
801 unsigned long arg)
803 int errno = 0;
805 unsigned minor = iminor(inode);
806 if (minor >= BPP_NO) return -ENODEV;
807 if (!instances[minor].present) return -ENODEV;
810 switch (cmd) {
812 case BPP_PUT_PINS:
813 set_pins(arg, minor);
814 break;
816 case BPP_GET_PINS:
817 errno = get_pins(minor);
818 break;
820 case BPP_PUT_DATA:
821 bpp_outb_p(arg, base_addrs[minor]);
822 break;
824 case BPP_GET_DATA:
825 errno = bpp_inb_p(base_addrs[minor]);
826 break;
828 case BPP_SET_INPUT:
829 if (arg)
830 if (instances[minor].enhanced) {
831 unsigned short bits = get_pins(minor);
832 instances[minor].direction = 0x20;
833 set_pins(bits, minor);
834 } else {
835 errno = -ENOTTY;
837 else {
838 unsigned short bits = get_pins(minor);
839 instances[minor].direction = 0x00;
840 set_pins(bits, minor);
842 break;
844 default:
845 errno = -EINVAL;
848 return errno;
851 static const struct file_operations bpp_fops = {
852 .owner = THIS_MODULE,
853 .read = bpp_read,
854 .write = bpp_write,
855 .ioctl = bpp_ioctl,
856 .open = bpp_open,
857 .release = bpp_release,
860 #if defined(__i386__)
862 #define collectLptPorts() {}
864 static void probeLptPort(unsigned idx)
866 unsigned int testvalue;
867 const unsigned short lpAddr = base_addrs[idx];
869 instances[idx].present = 0;
870 instances[idx].enhanced = 0;
871 instances[idx].direction = 0;
872 instances[idx].mode = COMPATIBILITY;
873 instances[idx].run_length = 0;
874 instances[idx].run_flag = 0;
875 if (!request_region(lpAddr,3, bpp_dev_name)) return;
878 * First, make sure the instance exists. Do this by writing to
879 * the data latch and reading the value back. If the port *is*
880 * present, test to see if it supports extended-mode
881 * operation. This will be required for IEEE1284 reverse
882 * transfers.
885 outb_p(BPP_PROBE_CODE, lpAddr);
886 for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
888 testvalue = inb_p(lpAddr);
889 if (testvalue == BPP_PROBE_CODE) {
890 unsigned save;
891 instances[idx].present = 1;
893 save = inb_p(lpAddr+2);
894 for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
896 outb_p(save|0x20, lpAddr+2);
897 for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
899 outb_p(~BPP_PROBE_CODE, lpAddr);
900 for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
902 testvalue = inb_p(lpAddr);
903 if ((testvalue&0xff) == (0xff&~BPP_PROBE_CODE))
904 instances[idx].enhanced = 0;
905 else
906 instances[idx].enhanced = 1;
907 outb_p(save, lpAddr+2);
909 else {
910 release_region(lpAddr,3);
913 * Leave the port in compat idle mode.
915 set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
917 printk("bpp%d: Port at 0x%03x: Enhanced mode %s\n", idx, base_addrs[idx],
918 instances[idx].enhanced? "SUPPORTED" : "UNAVAILABLE");
921 static inline void freeLptPort(int idx)
923 release_region(base_addrs[idx], 3);
926 #endif
928 #if defined(__sparc__)
930 static void __iomem *map_bpp(struct sbus_dev *dev, int idx)
932 return sbus_ioremap(&dev->resource[0], 0, BPP_SIZE, "bpp");
935 static int collectLptPorts(void)
937 struct sbus_bus *bus;
938 struct sbus_dev *dev;
939 int count;
941 count = 0;
942 for_all_sbusdev(dev, bus) {
943 if (strcmp(dev->prom_name, "SUNW,bpp") == 0) {
944 if (count >= BPP_NO) {
945 printk(KERN_NOTICE
946 "bpp: More than %d bpp ports,"
947 " rest is ignored\n", BPP_NO);
948 return count;
950 base_addrs[count] = map_bpp(dev, count);
951 count++;
954 return count;
957 static void probeLptPort(unsigned idx)
959 void __iomem *rp = base_addrs[idx];
960 __u32 csr;
961 char *brand;
963 instances[idx].present = 0;
964 instances[idx].enhanced = 0;
965 instances[idx].direction = 0;
966 instances[idx].mode = COMPATIBILITY;
967 instances[idx].run_length = 0;
968 instances[idx].run_flag = 0;
970 if (!rp) return;
972 instances[idx].present = 1;
973 instances[idx].enhanced = 1; /* Sure */
975 csr = sbus_readl(rp + BPP_CSR);
976 if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
977 udelay(20);
978 csr = sbus_readl(rp + BPP_CSR);
979 if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
980 printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
983 printk("bpp%d: reset with 0x%08x ..", idx, csr);
984 sbus_writel((csr | P_RESET) & ~P_INT_EN, rp + BPP_CSR);
985 udelay(500);
986 sbus_writel(sbus_readl(rp + BPP_CSR) & ~P_RESET, rp + BPP_CSR);
987 csr = sbus_readl(rp + BPP_CSR);
988 printk(" done with csr=0x%08x ocr=0x%04x\n",
989 csr, sbus_readw(rp + BPP_OCR));
991 switch (csr & P_DEV_ID_MASK) {
992 case P_DEV_ID_ZEBRA:
993 brand = "Zebra";
994 break;
995 case P_DEV_ID_L64854:
996 brand = "DMA2";
997 break;
998 default:
999 brand = "Unknown";
1001 printk("bpp%d: %s at %p\n", idx, brand, rp);
1004 * Leave the port in compat idle mode.
1006 set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
1008 return;
1011 static inline void freeLptPort(int idx)
1013 sbus_iounmap(base_addrs[idx], BPP_SIZE);
1016 #endif
1018 static int __init bpp_init(void)
1020 int rc;
1021 unsigned idx;
1023 rc = collectLptPorts();
1024 if (rc == 0)
1025 return -ENODEV;
1027 rc = register_chrdev(BPP_MAJOR, bpp_dev_name, &bpp_fops);
1028 if (rc < 0)
1029 return rc;
1031 for (idx = 0; idx < BPP_NO; idx++) {
1032 instances[idx].opened = 0;
1033 probeLptPort(idx);
1036 return 0;
1039 static void __exit bpp_cleanup(void)
1041 unsigned idx;
1043 unregister_chrdev(BPP_MAJOR, bpp_dev_name);
1045 for (idx = 0; idx < BPP_NO; idx++) {
1046 if (instances[idx].present)
1047 freeLptPort(idx);
1051 module_init(bpp_init);
1052 module_exit(bpp_cleanup);
1054 MODULE_LICENSE("GPL");